British royal Prince William has been officially knighted in Scotland.The third-in-line to the throne was appointed to the Order of the Thistle by his grandmother, Queen Elizabeth II, when he turned 30 last month (21Jun12), and he was formally installed as a member on Thursday (05Jul12) Prince William, who met his now-wife Catherine, Duchess of Cambridge while attending St. Andrews University in Scotland, wore a deep green velvet cloak and matching hat with an ostrich feather for the ceremony. The Order of the Thistle is the highest honour the Queen can bestow in Scotland and it is the Prince's second honorary knighthood - he was made an Order of the Garter at England's Windsor Castle in 2008.